PASADENA – Authorities have charged two men in the January 2008 slaying of 16-year-old Sammantha Salas in Monrovia.

Cousins Rayshawn Blackwell and Nickleis Blackwell were scheduled to appear in Pasadena Superior Court on Thursday for an arraignment, but the hearing was postponed to April 15.

Also Thursday, investigators said a third teen was with Salas and her friend when two men dressed in black hooded sweatshirts approached the group in the 2500 block of Peck Road and opened fire on Jan. 26, 2008, killing Salas and wounding her friend. The third teen, a boy, apparently ran when shots rang out.

The boy, an important eye witness to the shooting, had been difficult to locate until recently, said Los Angeles County Sheriff’s Department Lt. Dan Rosenberg.

He described the shooting as an “ambush-type attack.”

“Sammantha and her friends were standing in front of the apartment building when the suspects approached and opened fire without warning,” Rosenberg said. “Sammantha had no idea it was coming. Beyond that I can’t get into the specifics of the case.”

The case had remained unsolved, despite media coverage and a $20,000 offered by the county Board of Supervisors.

Jeanette Chavez, Salas’ mother, said she was notified of the arrests Wednesday evening.

“I’m really excited to hear about this,” she said. “I was able to sleep. And this morning I got up early.”

Chavez said following the case through the legal system won’t be easy.

“That’s going to be a challenge,” she said.

According to investigators, the shooting occurred during a turf battle last year between black and Hispanic gangs in the Monrovia area.

The Blackwells are nephews of 64-year-old Sanders Rollins, who was shot to death outside his Sherman Avenue home 13 days before Salas was killed.

Rosenberg said the Blackwells lived “off and on” at Rollins’ former home.

After another drive-by shooting in January of this year at the house, Monrovia officials declared it blighted and a hotbed for gang violence and moved to purchase and demolish it. The Monrovia Redevelopment Agency completed the purchase this month.

The Blackwells match a pair of composite drawings circulated by authorities late last year, Rosenberg said. The two suspects are associated with the Du Roc Crips, a primarily black Monrovia gang, he said.

“They’re definitely affiliated with the Du Rocs, if they’re not active members,” he said.

Tony Bell, a spokesman for county Supervisor Michael Antonovich, said it wasn’t clear whether the board’s reward offer played a role in the case.

“Supervisor Antonovich is obviously pleased that there are suspects in custody and we hope that this will get us closer to bringing justice to her family,” he said.

Monrovia Mayor Rob Hammond said the city has been working closely with the Sheriff’s Department and praised their work thus far.

“I think it’s fantastic that the homicide detectives worked so hard to bring to justice the killers of an innocent young woman,” he said.

Rosenberg said detectives worked the case as part of an investigative team that “worked under the radar” in Monrovia.

The unit was put together after a series of racially motivated gang attacks in Monrovia and Duarte between late 2007 and early 2008. Police said rivalries between the Monrovia-based Du Roc Crips, a black gang, and the Duarte Eastsiders and Monrovia Nuevo Varrio gangs – both primarily Hispanic gangs – led to much of the violence.

“We’ve been working all of these cases,” said Rosenberg. “Eventually, we developed enough information that led us to these suspects.”